October 14, 2019
Meta-Analysis Supports Endovascular Thrombectomy to Treat M2 Occlusions
October 15, 2019—A study conducted in response of the Society of Neurointerventional Surgery’s recent revision of its operational definition of emergent large vessel occlusion to include proximal M2 segment middle cerebral artery (MCA) occlusions sought to assess the benefit of endovascular thrombectomy (EVT) over best medical care for this condition.
Investigators conducting a meta-analysis of data from the HERMES Collaboration concluded that patients with proximal M2 segment MCA occlusions eligible for EVT trial protocols benefited from EVT. Bijoy K. Menon, MD, et al published the findings in the Journal of NeuroInterventional Surgery (2019;11:1065–1069).
Using patient-level data from trials in the HERMES Collaboration, the HERMES core laboratory identified patients with M2 segment MCA occlusions and further classified them as proximal versus distal, anterior versus posterior division, and dominant versus codominant versus nondominant. The study included 130 patients with M2 MCA (proximal location [n = 116] vs distal [n = 14]; anterior division [n = 72] vs posterior [n = 58]; dominant [n = 73] vs codominant [n = 50] vs nondominant [n = 7]).
The primary outcome was modified Rankin Scale (mRS) score 0–2 at 90 days. Secondary outcomes were modified thrombolysis in cerebral infarction (mTICI) rates at end of the procedure, 90-day mRS shift, 90-day mRS 0–1, 24-hour National Institute of Health Stroke Scale score 0–2, symptomatic intracerebral hemorrhage (sICH), and death.
In Journal of NeuroInterventional Surgery, the investigators reported the following:
- Successful reperfusion (mTICI 2b or 3) among those undergoing EVT was seen in 59.2% of patients
- Treatment effect favored EVT (adjusted odds ratio [OR], 2.39; 95% confidence interval [CI], 1.08–5.28; P = .03) for 90-day mRS 0–2 (58.2% EVT vs 39.7% control); direction of benefit favored EVT for other outcomes
- Treatment effect favoring EVT was maximal in patients with proximal M2 segment MCA occlusions (n = 116; adjusted OR, 2.68; 95% CI, 1.13–6.37) and in dominant M2 segment MCA occlusions (n = 73; adjusted OR, 4.08; 95% CI, 1.08–15.48)
- sICH was observed in no (0%) patients treated with EVT compared with five (7.9%) patients in the control arm.